Advantages and disadvantages of Q235 hot-dip galvanized square tube

2025-09-05 11:27:57

　　Q235 hot-dip galvanized square Rectangular pipe, as a commonly used structural pipe material, combines the mechanical properties of Q235 steel with the protective characteristics of hot-dip galvanizing process, and shows obvious advantages in practical applications. However, there are also certain limitations. The specific advantages and disadvantages are as follows:

　　1. Strong corrosion resistance and long service life

　　The hot-dip galvanized layer is tightly bonded to the substrate through metallurgical reactions, forming a uniform and dense protective layer (the thickness of the zinc layer is usually ≥ 85 μ m), which can effectively isolate the corrosion of steel by corrosive media such as air, moisture, acid and alkali. Compared to non galvanized "black pipes", their service life can be extended by 3-5 times (up to 15-30 years in ordinary outdoor environments), especially suitable for humid, rainy or mildly industrial polluted environments (such as outdoor buildings, municipal engineering, agricultural greenhouses, etc.).

　　2. Balanced mechanical properties to meet the basic load-bearing requirements

　　Q235 steel is a low-carbon structural steel with a yield strength of ≥ 235MPa and a tensile strength of 375-500MPa. It has good plasticity, toughness, and impact resistance, and can withstand basic loads such as structural support and frame connections. The cross-sectional shape of rectangular pipes makes them superior to circular pipes in terms of axial force and torsional performance, making them suitable as load-bearing components (such as scaffolding, guardrails, mechanical frames, etc.).

　　3. Excellent processing performance and convenient construction

　　It can be directly cut, welded (note the impact of zinc layer evaporation on weld quality, low hydrogen type welding rods can be used or welding parameters can be adjusted), drilled, cold bent and other processing can be carried out without complex pretreatment, suitable for on-site construction needs. In addition, the straight cross-section of the square tube facilitates connection with other components (such as bolt fixation and flange connection), resulting in high installation efficiency.

　　4. Moderate cost and high cost-effectiveness

　　Compared to stainless steel square tube, Q235 hot-dip galvanized square tube has lower raw material and processing costs; Compared with non galvanized Q235 square rectangular pipes, although it increases the cost of hot-dip galvanizing process, it has a higher comprehensive cost-effectiveness by extending the service life and reducing the cost of later maintenance (such as rust removal and paint repair), especially suitable for large-scale engineering applications.

　　5. Neat appearance, no need for additional painting

　　The surface of the hot-dip galvanized layer is silver white (or with natural zinc flowers), with a uniform and beautiful appearance. It can be directly exposed for use, saving the cost and process of secondary coating. It is suitable for scenes with basic appearance requirements (such as billboard brackets, landscape guardrails, etc.).